Exemplary embodiments relate to an image resolution converting technology. More particularly, exemplary embodiments relate to a method and a device for enhancing details and sharpness, as well as efficiently removing visual artifacts included in a high resolution image, converted from a low resolution image.
Recently, a display supporting a full high-definition (FHD) resolution or an ultra high-definition (UHD) resolution has become popular. However, contents of a related art broadcast or film has been made with a standard-definition (SD) resolution or a high-definition (HD) resolution. Since the production cost of a high resolution image is more expensive than a low resolution image, the low resolution image is still produced.
When a user tries to watch a low resolution image through a high resolution television, the low resolution image needs to be expanded (i.e., converted) into a high resolution image. In addition, as a small electronic device, i.e., a smart phone, is developed, the small electronic device provides a function of expanding (i.e., converting) a low resolution image into a high resolution image.
Once a low resolution image is expanded or converted into a high resolution image, various problems may occur. For example, a jagging may occur at an edge of a diagonal line or a ringing may occur around the edge. Further, when a high frequency component is added or enhanced for improved image quality, a noise occurs in a low frequency component region. Additionally, sharpness is deteriorated by slow edge changes, and details of an image are lowered when a high frequency component is eliminated.